Experimental and theoretical radiative lifetimes, branching fractions, andoscillator strengths for LuI and experimental lifetimes for LuII and LuIII

Radiative lifetimes, accurate in most cases to +/-5%, from time-resolved, l aser-induced fluorescence measurements on a slow beam of lutetium atoms and ions are reported for 22 odd-parity levels and 4 even-parity levels of Lu I and 14 odd-parity levels of Lu II. In addition, we report the radiative l ifetime of one odd-parity level and an upper bound on the radiative lifetim e of a second odd-parity level of Lu III. Experimental branching fractions for Lu I from emission spectra covering the near ultraviolet to the near in frared and recorded using the US National Solar Observatory 1.0 m Fourier t ransform spectrometer are reported. The branching fractions are combined wi th the radiative lifetimes to produce 44 experimentally determined transiti on probabilities or oscillator strengths, accurate generally to +/-10%, for Lu I. New theoretical values for Lu I radiative lifetimes and branching fr actions from a relativistic Hartree-Fock calculation that includes core pol arization effects are also reported. These experimental and theoretical res ults, as well as older published results, are compared.